A bus rider starts shaking and sweating. A man comes into an office acting belligerently and shouting. A woman mumbles to herself as she wobbles down a sidewalk.

Such behavior tends to disturb or scare people who don't realize it could signal mental illness or distress. If they learned to recognize the signs, they could provide initial comfort in crises and prevent harm to the sufferers or others, say proponents of a relatively new concept called mental health first aid.

Stepping in with special listening and questioning skills can diffuse difficult situations, guide sufferers to treatment quicker and lessen the stigma surrounding mental illness, advocates say.

"You're more likely to encounter somebody with depression or suffering a panic attack than somebody having a heart attack," said Viviana Ploper, associate director of Community Counseling Centers of Chicago, which brought mental health first aid, a concept developed in Australia, to the region several years ago. "You don't have to be a professional to recognize when somebody is struggling. You listen and encourage the person to get help in a respectful way."

Judy Scott, 67, a patient advocate and recovery specialist at Chicago Read Mental Health Center, knows firsthand how hard it can be to ask for help. Little has changed as far as the stigma of mental illness, she said, since she was diagnosed with what's now called bipolar disease when she was 24.

"I can envision a mom and dad who have a mentally ill child getting more understanding," said Scott, who took the 12-hour mental health first aid course almost a year ago. "My mom never understood, never went with me to a psychiatrist. She thought she was somehow responsible."

The idea is to turn bystanders into "upstanders" who speak up instead of staying on the sidelines, said Cliff Saper, a clinical psychologist and executive director of outpatient programs at Alexian Brothers Behavioral Health Hospital in Hoffman Estates.

Rather than judging the mumbler on the sidewalk to be drunk or high and crossing the street to avoid him, a person trained in mental health first aid approaches him with questions designed to calm him and identify what help he might need.

It's part of cultivating a "culture of compassion," said Saper, citing similar methods the hospital uses in teaching about bullying and in crisis intervention when communities are ravaged by weather or other disaster. "Mental health is as important as physical health."

Having the confidence to ask a person whether he intends to harm himself can open the door to a conversation that can avert a suicide, said Teran Loeppke, a community organizer in Chicago who has handled such situations since taking the mental health first-aid course.

"People don't talk about these things, and the training increased my sensitivity," said Loeppke, who also is an ordained deacon in the United Methodist Church. "Before I would have shied away. But it's important to ask questions."

Community Counseling Centers of Chicago, which operates five facilities for the mentally ill on the North Side, cautions course participants that what they learn will not qualify them to diagnose or treat mental illness.

The participants master a five-step action plan, known by the acronym AGLEE, for handling mental health issues. AGLEE stands for assess risk of suicide, listen nonjudgmentally, give reassurance and information, encourage appropriate professional help and encourage self-help and other support strategies. Participants are given questions to ask — and not to ask — to help them deal with those in need of aid.

Bob Brophy, director of residence life at University Center student housing, which serves four colleges in downtown Chicago, said counselors and security personnel regularly see roommates at each other's throats and students who are anxious, depressed and homesick. While they are trained in conflict resolution and de-escalation techniques, mental health first aid gives them new tools, Brophy said.

"The acronym is helpful when people are screaming at you. You can go to a place in your mind," he said, and act to calm things down. "It's all about getting people to relax and be more cooperative.

"We refocus our priorities on how to help in dire situations. If I can talk you off a ledge, then I can get you to professional help."

Attention has been directed toward campuses after numerous mass shootings around the country and research that shows suicide to be the second-leading cause of death among those ages 10 to 24. In addition, the onset of serious mental illness tends to be during college years, said Meena Dayak, vice president for marketing and communication of the National Council for Community Behavioral Healthcare in Washington, D.C.

A mental health first-aid course directed toward youths and those who teach, counsel and work with them is being rolled out in September, she said. Plus, the organization is behind legislation recently introduced in Congress that calls for mental health first aid to be taught at 10 institutions of higher learning over five years as a test program.

The concept of mental health first aid, exported to the U.S. about four years ago by the council and others, is a front-lines piece of a treatment net that seeks to snare more of the estimated 1 in 4 Americans who suffer a mental disorder each year. There's a big human and societal price tag for not recognizing and treating the mentally ill, Dayak said.

Ploper said realizing that a person on a bus is having a panic attack and calmly asking if it's happened before, helping to steady his breathing and pointing out that professional assistance is available is the kind of early intervention that might prevent the development of the more debilitating panic disorder.